Embodiments disclosed, herein relate to methods for purification of IgG monoclonal antibodies.
Purification of recombinant proteins commonly begins with a so-called primary capture step, in which cells and debris are removed so that the remaining supernatant can be processed by methods that would be hampered or rendered ineffective by the presence of cells and debris. Their removal commonly involves centrifugation and filtration. It sometimes involves the use of membrane or depth filters with anion exchange capabilities, or the addition of anion exchange particles directly to the antibody-containing harvest (Gagnon, P., Purification Tools for Monoclonal Antibodies, Validated Biosystems, Tucson, 1996; Kuczewski, M, et al, Biopharm Int 23 (3) (2010) 20-25; Kuczewski, M., et al, Biotechnol. J., 6 (2011) 56-65), in all such cases reportedly to reduce levels of host cell proteins (HCP). Brodsky et al (Biotechnol. Bioeng. 109 (2012) 2589-2598) described HCP precipitation by caprylic acid as a precursor of subsequent purification by protein A affinity chromatography. Gan et al (J. Chromatogr. A 1291 (2013) 33-40) employed a different approach of preparing a harvest for subsequent chromatographic purification by specifically targeting a subset of host cell contaminants derived from chromatin, consisting chiefly of histone proteins and DNA. One of those method particularly employed a combination of soluble multivalent organic cations to dissociate aggregates, and insoluble (surface immobilized) multivalent organic ions to remove remaining aggregates and other contaminants. They also described the inclusion of allantoin among the active ingredients to achieve their results.